Method of and apparatus for measuring temperatures



May 20 1924. 1,494,586

C. R. CARY METHOD OF AND APPARATQS FOR MEASURING TEMPERATURES Filed Feb. 26, 1921 2 $hoets-Sheet 1 a If 2 ATTORNEY.

May; 20 1924.- V 1,494,586

C. R. CARY METHOD OF AND APPARATUS FOR MEASURING TEMPERATURES Filed Feb. 26', 1921 2 Sheets-Sheet 2 1 ATTORNEY.

Patented May 20, .1924.

UNITED STATES PATENT- PENNSYLVANIA, assreivon T0 LEEDS & NOBTHRUP- comramr, orrmannnrnra, rmmsnvanm, aconrona'rron on CHARLES R CARY, on rmnannnrnm,

PENNSYLVANIA.

KETHDDOE AND APPARATUS FOR MEASURING TEMPmTURIS.

-App1ication filed February 26, 1921. Serial no. 448,616.

To all whom it may concern: A Be it knownthat 1, CHARLES R. Cannacitizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented new and useful Improvementsin Methods of and Apparatus for Measuring Temperatures, of which the following is aspecification. 7

My invention relates to a method of and apparatus for measuring, recording or con- I trolling temperature, as by thermo-electric or equivalent means.

In accordance with my invention, the.

average of a plurality of temperatures, such, for example, as may simultaneously exist at dliferent places or points, is directly measured, recorded or employed for efiecting any motive-forces to operate cumulatively upon suitable control, by producing electro-motive-forces, as by thermo-electric or equivalent means, corresponding with the ditferent temperatures, and causing such electroa'galvanometer or with a potentiometer, or equivalent arrangement, the galvanometer deflection corresponding with a'temperature which is the average ofthe several temperatures.

Further in accordance with my invention,

the several thermo-electric or equivalent Further in accordance with 'my inveritioh,

the above described switchin mechanism may be actuated or automatica y controlled in association with the recorder mechanism.

Furtherin accordance with-my invention, 7

the temperature-responsive devlces, as thermo-electnc or equivalent means, may be brought individually or in series withea'ch other intorelation with a galvanometer, which latter, under the difierent conditions of individual and collective use ofthe tem:

perature responsive devices, is brought into. association with difierent potentiometer circuits err-equivalents, the clifierent potentiometers, or equivalents, preferably also being switched into and out of circuit in umson with the above mentioned switching mechanism.

My inventionresides in the method and double scale my invention.

Fig. 3 is a diagrammatic view of the electrical circuits utilizable in connection with the recording or control mechanism.

Fig. '4; is'a cross sectional view, partly in elevation, of switching mechanism.

Referring to Fig. 1, V is a voltmeter or millivoltmeten'or other suitable deflecting galvanometer, preferably of the DArsonval type, having the deflecting needle or pointer a, and the scaleb. .The thermo-junct-ions T, T and T are connected in series with each other and the galvanometer V, the cold junctions of the thermo-couples' being preferably at the instrument V, this being accomplished, as well understood in the art, by using as leads from the thermo-junctions to the instrument conductors of the same materials of which the junctions are formed.

Thethermo-junctions are locatedat the dif- V ferent places or points the average of the "temperatures'at which is to ,be measured.

7 The thermo-junctions may be located at difi'erent -points longitudinally of a slot of an armature of a dynamo-electric machine,

and are preferably located between neighboring coils or conductors in the slot. Or

the thermo-junctions may be located in any other difierent places, as in different bins or housings of a grain storage house or elevator; in difie'rent parts of a furnace, etc."

- Each thermo-junction partakes of the temperature of the place where located, and roduces an electro-motive-force correspondmg to such temperature, By serially concated in Fig. 2. 7 The governed electric motor M rotates the,

movable or controlled structure.

necting the thermo-couples as indicated, the

electro-motive-forces producedthereby operate cumulatively upon the 'falvanometer V, causing it to produce a de ection which corresponds'with the sum of the electro-motive-forces produced by the different thermojunctions, and such deflection is therefore a. measure of the average of the several temperatures to which the several junctions are subjected.- For examle, if the galvanometer V were calibrate in millivolts and its deflection corresponded to say, 24 millivolts, the average temperature would be that corresponding with one-third, or 8 millivolts.

The scale I; of the galvanometer may be calibrated to read directly in average voltages, as by dividing each reading of the usual millivolt scale by a number corresponding with the-numberof thermo-junctions employed in I series witheach other. On the scale may have, as indicated in Fig. 1, two graduations or scale 6 and 0, one of them as reading direct y in the usual milliyolts, and the other has 6 in terms of such 'millivolts divided by the number of thermo=junctions in series. ;Or in lieu of either or both of the millivolt scales may be employed temperature scales. Thus, the scale bmay have two temperature scales, one employed whenbut one thermo-junction is in circuit with the instrument, and the other reading in average temperatures and employed when the several thermo-junctions are in series with the instrument.

When the double scales are employed reading either in millivolts or temperatures, or both,

switching mechanism of the character herea inafter described may be employed for connecting' the thermo-junctions individually in circuit with the instrument orin series with each other as indicated.

For recording or control purposes, any

suitable mechanism may be employed under 1 .the control of the thermo-junctions, ortheir equivalents.

In the example illustrated in Fig 2,- the recording or control mechanism may-be of the character disclosed in Letters Patent of the United States No. 1,125,699, granted to M. E. Leeds J anuary 19, 1915, forvclearness only the principal parts being findishaft 8 at uniform speed through the :me-

"dium of the worm 6 and worm gear 7.

Horizontally pivoted near its upper end is .the lever 21, to which is pivoted at26 the arm 27 having at eachend a shoe 28,.of

cork or other suitable material, for fric-- tionally engaging the rim 29 of the disk or wheel 30 secured upon the shaft 31 of the Secured upon the shaft 8 is a cam 32, which periodical 1y engages the lever 21 and lifts the shoes 28 from the rim of the wheel 30. Secured the shaft 77 b to the shaft 8 is a second cam 33' which, im-

shoes 28 from the wheel 30, engages the end of finger 34 upon the arm 35 secured to the frame 37 piyoted at 38. The frame 37 carries the member 40, between whose upper edge 41 and the lower edges 44 of.members -mediately after the cam 32'has lifted the" 45 is adapted to deflect laterally the needle or pointer 42 deflected by the coil 0 of the galvanometer. The members 45 are integral with the downwardly extending members 48, drawn toward each other by .sprin 49, and pivoted at 46. The lower ends 0 the arms 48 co-act with the pins 50 on the ,plate '51 attached tothe arm 27, which latter has the lugs or ears 57 with which coast the cams 58 secured upon the shaft 8. Secured upon the shaft 31 is the wheel or .pulley 59 around which is wrapped a cord 60 driven thereby and passing over idlers 61 and attached to the carriage or member 63 laterally slidable upon the guide rod 64. The marker of the recorder. may be of any suitable type, as a pen, pencil or other point or line-drawing or printing device. Ashere illustrated, it is the marker of a multiple point recorder, and takes the form of a wheel 66 carrying a plurality of types or other printingcharacters 67, in the example illustrated, where three temperature responsive devices are employed, there being four characters, one for each individual temperatureresponsive device, and another for the temperature responsive devices when connected in series with each other. The

type wheel 66 is movable longitudinally of the carriage 63, and is rotated by the s aft 77, as described in said Letters Patent. The type wheel co-acts with the recorder paper 97 stored upon the roller 98' and unwound therefrom on to the roller 95. Secured upon the shaft 31 is the wheel or disk of insulating material 122 upon which is disposed the resistance conductor R, with which co-acts the stationary brush or contact 123.- Similarly movable with the shaft 31 is the second resistance conductor R, which may be carried upon thedisk 122 or which, as indicated, may be carried upon a separate disk 10, the station .ary brush or contact. 11 co-acting with the resistance .RE 1 V v Switchingmechanism may be manually operated, or it may be operated in association with the recorder. mechanism by the 0, is indicated in Fig. 2, is shown as related through the switching mechanism S with the split circuit potentiometers P and P having, if desired, the common source of current or battery B connected with the potentiometers through the variableresistance or rheostat d. The potentiometer. P com-r prises the aforesaid resistance R andv resistance .e in one branch, and the resistances f and g in theparallel branch, the resistances R, e and g having preferably zero a temperature co-eflicients, while the resistance 7' preferably has a positive temperature co-efiicient and may consist of nickel, this arran gement being suitablefor compensating for variation of temperature at the cold junctions of the thermo-junctions T T and T in accordance with Letters Patent of the United States No. 1,199,724, September 26, 1916. Similarly,,the potentiometer P comprises the aforesaid resistance R and resistance h, and in the parallel branch the resistances z and j, the resistances R h and 9' preferably having zero co-efiicients, while the resistance i may again be of nickel as in the case ofpotentiometer P.

The terminals of the galvanometer G connect with the brushes k. and mbearing, re-- spectively, upon the slip rings at and 0, Figs. 3 and 4, the ringn being ermanent-ly in electrical communication with the'rotatable brush or contact p and the slip ring 0 being permanently in 'electricalcommunication with the brush or contact g, the brush 3) in its above positions during rotation contacting with the switch contacts or segments 1', s, t and u, while, the brush 9 engages the switch contacts or segments '0 and w, of which o occupies, approximately three fourths of acircumference, and the contact w one-fourth, when three thermo-junctions areemployed. A third brush m, Fig. 3, beans with its one end upon the switch contacts or segments 3 z, a and 6 while its other end bears upon the switch contacts orsegments c and (2 positioned similarlyto the contacts o and w and having similar angular extents. The slip rings n, 0 and the ,brushes p, g and a: are rotated in unison by the shaft 6 which may be rotated by mechanism similar to that described in said Leeds Patent1.125,699 for rotating the switch contact 107 thereof. i

As indicated in Fig. 3, the segments or contacts 1' and 2 are connected together, as are also 8,12 t, 6 my.

p The stationary brush or contact 123, coacting with the resistance R of potentiometer P, is connected by conductor f 'with the aforesaid contact 22, and the contact c is connected-by conductor 9 with the-"other branch of the potentiometer P between resistances f and g; Similarly, thestationary brush 11, oo-acting with the i sta ce"R of the potentiometer P connects by conductor k with the contact w, and the contactd connected by, conductor 5 with the other branch of the potentiometer P between the resistances i and 1 v With the switch brushes in the position indicated in Fig. 3, it will be found that the thermo-junction T and galvanometer G are connected in series with each other and associated with the potentiometer P by connectioii between the brush 123 and a point between the resistances f and 9'. With the switch brushes rotated in clockwise direction as viewed in Fi 3 through a quarter of a revolution, the tiiermo-junction T will be in series with the galvanometer Gr and similarly related to the potentiometer P. Upon a further quarter revolution the thermo-junction T will be in series with the galvanometer G and similarly related to the potent-iometer P. But upon a further quarter revolution, the potentiometer P will be out of circuit, and the thermojunctions T T, T will be connected in series with each other and the galvanometer G between the brush 11 of the potentiometer P and a point between its resistances 2' and y.

Accordingly, the switchingmechanism is such as to bring the different thermo-junctions successively into co-action with the Q galvanometer G and the potentiometer P,

a and then the three thermo-junctions'in series with each other and the galvanometerG in relation to the potentiometer P The potentiometers P and P -difier .as

the magnitudes of their resistances', thex re sistances of the potentiometerP being suited to the relatively lower electro-niotive--1orceas produced by a single thermo-junction,

while the resistances of the potentikiihetel'jl? Y Y are suited for co-action with relatively higher electro-motive-force, such as the 0f the electro-motive-forces of, the severe mo-junctions.

The operation is asfollow's 1 When any one of the thermo jun I in circuit,vthe apparatus indicated in'Figs. 2 and 3' operates asdescribed in said Letters ctions "is Patent to Leeds, the apparatus'auto'matical- 'ly rotating the movable structure, comprising the shaft 31 and attached parts, in such direction and extent as tocause' the resultant adjustment of the resistance R, by movement with respect to brush 123, to re-balanc'e or 'tend to re-balance the potentiometer P,

r as corresponds to the temperature to which v case presented to the paper or recor is made of each-0f a plura the thermo-junction is' subjected. However, periodically all the thermo-junctionsare brought into series with each other and related to the potentiometer P in which case the operation of the mechanism issimilar, the resistance R in this case re-balancmg or tending to re-balance the potentiometer P by movement of the resistance R with re spect to the stationary brush 11, the fourth c aracter of the type wheel 66 bein in this d sheet. Accordingl record is'made of the different indivi u'al temperatures, and a sep-j a scale 12 reading in terms of temperature,

electro mfotive force, or both; and similarly, there may be associated with the resistance R, as by appl ing the same to the disklO, a scale 13 me ing in units-of temperature or electro-motivesforce or both, the rotating scales co-acting with any suitable sta tionary indices or pointers, as 14, 15, whereby the electro-motive-forces or temperatures may be measured or read.

Whether or not the mechanism described produces a record, the movable structure,

comprising shaft 31 and attached parts, is controlled inresponse to the individual temperatures and the average temperature or may be employed to efiect any suitable control; as a control which willmodify .the individual electro-motive-forces or their average or com site electromotive-force;.or it may. contro the application of a heating agent tovary. or control the individual temperatures or to vary or control the'average temperature. a t

For these purposes temperature control apparatus such as disclosed in Letters Patent No'. 1,332,182and No. 1,356,084, to Leeds and Brewer, respectively, or for variation 01' controlof electro-motive-force, as disclosed in Keelerapplication Serial No.

374,267, may be employed.

What I claim is:

lnThe method of contrdl which consists in producing electro-motive-forces representative of diiferent magnitudes of a condi- I said means connecting said thermo-couples 1 tion, causing said electro-motiveforces to operate cumulatively, impressing the composite electro-motive-force upon a control instrument to produce a deflection thereof representative of the average of said magnitudes, and efiecting a'control by said de- V l v.

2. The method of control which consists n produc nga plurality of electro-motivement whose deflection is representative of (o the average of said temperatures, and effecting a control by said deflection.

' 3. Apparatus for effecting a control in response to the average of a pluralit of magnitudes of/ a condition, comprising 76 means roduclng an electrical efi'ect varying wi variations of each magnitude, a defleeting member responsive to. the cumulative efiect of said electrical efiects, amovable structure, means for moving said structure, andmeans controlled by said deflecting member controlling the co-action of said movable structure'and said means for moving it.

4. Apparatus for effecting a control in 35 response to the average of a plurality of temperatures, comprising means producing an electro motlve-force varying with variations of each temperature, a galvanometer subjected to the sum' of 'saidelectro-motiveforces, a movable structure, a source of power for moving the same, and means controlled by said galvanometer controlling actuation of said movable structure by said a source of power. l

5. Apparatus for effecting a control in response to the average of a plurality of temperatures, comprising a thermo-junction subjected to each temperature, a balancing circuit, a ga .vanometer therefor, means connecting'sai thermo-couples in series with each other and said galvanometer, a 'movable structure,'a source of power, and means controlled by said galvanometer controlling actuationofsaid movable structure by said source of power.

6. Apparatus recording individual magni-,

tudes of a condition and their average comprising a marker, meansfor vmoving the same, a galvanometer controlling means, an electrical devlce responsive to each of said magnitudes, and switching mechanism operated by said means for relating said galvanometer to said responsive} devices individually and collectively.

7. Apparatus for recording individual temperatures and their average comprisinlg a marker, means for moving the samega ga vanometer controlling said means, a thermocouple subjected to each of said tempera- 1 tures, and switching mechanism actuated by with said galvanometer individually and col lectively.

temperatures and their average comprisin a thenno-couple subjected to each -of sai temperatures, a galvanometer, a marker controlled bye-said galvanometer, a plurality of otentiometers, and switching mechanism said 8. Apparatus for recording individual messes for relating said galvanometer and said thermo-couples individually with one of said Potentiometers and for connecting said thermo-couples in series with each other and said galvanoineter and relating them to another of said potentiometers.

'9. Apparatus for measuring the average ofa plurality of temperatures comprising a thermocouple subjected to each temperature, means for connectin said thermo-couples in serieswith each other to render their electro-motive-forces cumulative, a deflecting galvanometer subjected to the cumula tive effect of said electro-motive-forces, and a scale for said galvanometer calibrated in units of averages of said electro-motiveforces.

10. Apparatus for measuring the average of a pluralit of temperatures comprising a thermocoup e subjected to each temperature, means for connectin said thermo-couples in series with each ot er to render theirelectro-motive-forces cumulative, "a deflecting galvanometer subjected to the cumulative effect of said electro motive-forces, and a scale for said galvanometer calibratedin units of averages of said temperatures.

11. Apparatus for measurin magnitudesanciug circuits, and switching mechanism for relating a plurality of said electrical de:

' vices individually with one of said balancing circuits and for relating a plurality of said electrical devices in series with each other to another of said balancing circuits.

13. Apparatus for measurin magnitudes ofa condition individually an collectively,

comprising a plurality of electrical devices".

subjected, respectively, to the difierent magnitudes of the condition, a plurality of balancing circuits, a galvanometer, and switching mechanism for relatin a plurality of said electrical devices individually with one of said balancing circuits and said galvanometer and for relating a plurality of said electrical devices simultaneousl with said galvanometer and another of sa1d balancing circuits. a

14. Apparatus for measuring individualv magnitudes of a condition and their average, comprising a plurality of electrical devices subjected, respectively, to thedifferent 1 magnitudes of the condition, a plurality of balancing circuits, a galvanometer, and switching means for relating a plurality of said electrical devices individually with one of said balancing circuits and said galvanometer and for relating a plurality of said electrical devices in series with each other to said galvanonieter and another of said balancing circuits.

15. Ap aratus for measurin magnitudes of a con ition individually an collectively, comprising a plurality of electrical devices subjected, respectively, to the difierent ma nitudes of the condition, a plurality of ba ancing circuits, a source of current common to sand balancing circuits, and switching mechanism for relating a plurality of said electrical devices individually with one of said balancing circuits and for relatin a plurality of said electricahdevices simu taneously with another of said balancing circuits.

16. Ap aratns for measurin individual magnitu es of a condition and t eir average, comprising a plurality of electrical devices subjected, respectively, to the different magnitudes of the condition, a plurality of balancing circuits, a source of current common to said balancing circuits, and switchin mechanismfor relating a plurality of said electrical devices individually with one of said balancing circuits and'for relating a plurality of said electrical devices in series with each other to another of said balancing circuits. I j

17. Apparatus for m'e'asurin magnitudes of a condition individually an collectively,

comprising a plurality of electrical-devices" subjected, respectively, to the difierent magnitudes of the condition, a plurality of balancing circuits, a source of current common to said balancing circuits, a galvanometer, and switchin mechanism for relating a plue rality of sai electrical devices individually with one of said balancing circuits and said galvanometer and for relating a plurality of said electrical devices simultaneously with said galvanometer and another of said balancing circuits.

18. Apparatus for measuring individual magnitudes of a condition and their average, comprising a plurality of electrical devices subjected, respectively, to the different magnitudes of the condition, a plurality of balancing circuits, a source of current common to said balancing circuits, a' galvanometer, and switching means for relating a plurality of said electrical devices individuallywith one of said balancing circuits and said galvanometer and for relating a plurality of saidelectrical devices in series with each other to said galvanometer and another to said balancing circuits. V

19. Apparatus for measuring tempera tures individually and collectively, compris- 'ing a plurality of electrical temperature-responsive devices subjected, respectively, to t a different temperatures, a plurahty of balancin circuits and switchin mechanism for relating said devices indivi ually to one of saidbalancin circuits and collectively to another of said alancing circuits.

Apparatus for measuring individual temperatures andtheir average comprising a plurality of electrical temperature-respon- T sive devices subjected, respectively, to the diflerent temperatures, a lurality of balancin circuits, and switc ing mechanism for re ating said devices'individually to one of said balancing circuits and in series with each other to another of said balancing circuits.

21. Apparatus for measurin' temperatures individually and collectively comprising'a plurality of thermo-couples subjected, respectively, to the different temperatures, a plurality of potentiometer circuits, and switching mechanism for relating said thermo-couples individually to one of said potentiometercircuits and collectively to an-- othr of said potentiometer circuits.

22. Apparatus for measuring individual temperatu es and their averagecomprising a plurality of thermo-couples subjected, re-

spectively, to. the difierent temperatures, a,

plurality of. potentiometer circuits, and switchlng mechanism for relating said thermo-couples individually'to one of said potentiometer circuits and in series with each other to another of said potentiometer circuits. p V

23. Apparatus for recording magnitudes of a condition individually and collectively comprising recording mechanism comprisinga record sheet and marking mechanism,

I v a plurality of electrical devices subjected, re-

spectively, to the different magnitudes of the condition, a plurality of balancing clrcuits, and switching mechanism for brin in said recording mechanism under contro 0 said balancing circuits individually and for rep lating said electrical devices individual]? sheet and marking mechanism having a plu-' rality of marking elements, a plurality of electrical devices subjected, respectively, to the individualmagnitudes of the condition, a plurality of balancing circuits, switching mechanism for bringing said recorder under control of said balancing circuits individually and for relating said electrical devices individually to one of said balancing circuits and collectively to another of said balancing circuits, and means for operating said switching mechanism and said marking mechanism to cause different marking ele-' ments to be presented to said record sheet when diflerent of said electrical devices are related to one of said balancing circuits and for bringing another element of saidmarking mechanism into operative relation with said record sheet when said electrical. devices are collectivelv relatedtoianotherof' said balancing'circuits. a

In testimony whereof I have hereuntofaffixed my signature this 24th.,day'offFeby, 1921. 

